共查询到19条相似文献,搜索用时 109 毫秒
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干燥过程特性和干燥技术的研究策略 总被引:9,自引:1,他引:9
从对干燥过程特性认识的进展,变温干燥方法对提高干燥过程速率及防止降速干燥阶段物料变质的作用、干燥过程强化、节能和产品质量之间的关系,干燥理论和干燥过程模型化的进展及存在困难,以及近年来国际上对干燥技术的关注重点等方面为依据对我国的干燥技术研究策略作了简要的评述。 相似文献
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Curative compositions such as catolpol in Rehmannia Glutinosa, flavone in Ophiopogon Japonicus and ginsenoside Re in Panax Ginseng in Chinese herbs were measured as the experimental indices by the method of high performance liquid chromatography under different drying conditions. The reaction order and parameters of the degradation kinetics model were determined and the model was verified by experiments. It was indicated that by comparing with the thin drying method, the prospective model could predict the degradation of curative compositions with drying time, temperature and moisture content of herbal materials with enough precision and could be used to simulate the degradation in the drying process of Chinese herb. 相似文献
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电石、铁合金等行业需要用干燥的焦丁做原料。早期焦丁价格在500~700元/吨左右,成本比较低;近年来,焦丁价格现在已经达到了1500元/吨以上,焦丁和焦末的差价已达500元/吨以上。随着项目规模大型化的发展趋势,原来传统的回转干燥工艺系统焦炭丁在干燥过程中的破损率过大对生产成本的影响已经不容忽视,立式干燥工艺系统由于其低破损率在电石等行业日渐倍受青睐。 相似文献
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针对颗粒和空气在干燥管内的相互作用和传质传热机理,首先建立了直管式气流干燥数学模型,然后通过分析脉冲式气流干燥器的结构特点,求出了管径变化的微分方程,将其和直管式气流干燥的五个常微分方程耦合在一起,构成了脉冲式气流干燥的传质传热数学模型。根据模型方程的特点,运用四阶龙格-库塔法对其进行了数值求解。通过实验结果验证,该模型正确可靠。 相似文献
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本文对用于造粒和包涂过程的顶喷流化床内的干燥过程进行了较为详细的实验和理论研究。从传质传热过程中分析可知,床层可分为三段。影响生产能力的最大允许喷淋速度受流化空气流量和入口温度影响最大。 相似文献
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Antti Hukka 《Drying Technology》2013,31(3-4):1213-1229
ABSTRACT An existing drying simulation model for softwood heartwood is revised lrom a theoretical point of view and is completed by extracting all the essential material parameters from moisture and temperature profiles measured in direct drying experiments. Some additional experimental results are presented to validate the qualitative characteristics of the model. The resulting computational model shows good agreement with experiments in the drying temperature range 45-120°C. Special attention is paid to the evolution of moisture gradient during drying, as the next step of the simulation project will be using the result as an input data for a computational stress model. 相似文献
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本文通过对无机纤维板干燥过程的分析,建立了干燥过程中热量传递和质量传递的数学模型,模拟结果与实测结果有较好的一致性. 相似文献
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Salts and chemical fertilizers, such as potash, have a strong tendency to cake when exposed to humid air. This paper examines the recrystallization process between potash particles as a result of water evaporation after the particles have been previously wetted. A theoretical/numerical model is presented to simulate binary ion diffusion and crystallization near one contact point between two potash (KCl) particles during a typical drying process. The effects of three independent factors are investigated, initial moisture content, evaporation rate, and degree of supersaturation on the surface surrounding the contact point. In part I of this two‐part series of papers, this problem is formulated subject to specific boundary conditions and initial conditions and the method of numerical analysis is presented. 相似文献